BUG: Fix test failures and interactor problems on 64-bit Windows builds. Define vtkLONG to be LONG to use with SetWindowLong or LONG_PTR to use with SetWindowLongPtr. Use multiples of sizeof(vtkLONG) instead of hard-coded 4's and 8's. BUG: Fix problem where any Win32RenderWindow close would cause a PostQuitMessage from the interactor... Only call PostQuitMessage from an interactor if that interactor's Start method was called to begin a message loop.